Automatic relief-valve for fluid-impelling apparatus.



A. G. E. RATEAU. AUTOMATIC RELIEF VALVE FOR FLUID IMPELLING APPARATUS.

APPLICATION FILED NOV. 20, 1906.

1,052,172. Patented Feb. 4, 1913.

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,A T A I a LIEF-V VE FOB ELUIDampsrinmeiarraayrnsf '3 I Specification 01 Letters Patent. 7 2 I 'Appli cat ion'filed November 20, 1906. Serial No.344,'351".'

To all whom it may concern Be ,itfiknown that I, AUGUSTE CAnrILLE EDI/[01 m 'RATEA'U, citizen of'the Republic of France, residing at Paris,- France, have in-l vented a certain new and useful Improvement in Automatic Relief-Valves for Fluid- Impelling Apparatus, of which the following is a full, clear, concise, and exact description.

Myinvention relates to an automatic relief-valve for fluid impelling apparatus, and

its object is more particularly to provide means for preventing surging and'vibration in compressors ofthe' turbine type, i. 6., cen-- trifugal or helicoidal compressors. In the use of centrifugal impellers for compressing elastic fluid, such as" ai'r or gas, at high pressures, one of the'difiicult1'es encountered is that the currentof air or gas becomes pulsatory or urging-when the discharge is relatively weak. For example, in the case of a centrifugal compressorjrecelving airfrom the atmospliereanddischarging it into a reservoir where the air is already under pressure, itis necessary to provide between the. reservoirf and the compressor-alcheckvalve which automatically closes to prevent back-flow from the reservoir when the pres-'1 the check valve is-stronger than the oppossure from the compressor'is insufli'cient. If this check-valve closes while the compressor remains iii operation,- the elastic' flu d takes on a pulsat'ory' or surging movement, going and coming'alternately at variable periodsof time according to circumstances. "Violent vibrations and shocks are thus set up i in the apparatus, and these will persist un til the discharge. of air reaches a high pressure sufficient to hold the check-valve open.

vSuch 'surgingfand vibration, furthermore,"

occasion "a considerable loss of energy, which is manifested in the heating of the air, and of the machine itself. To overcome this difficulty, the present invention contemplates the provision ofmeans for opening an independent outlet for the' discharge when the working load becomes of such value as would tendtoset up surging or vibration.

I will describe myinvention more particularly by reference to the accompanying drawings, in wh1ch- Figure 1 is a diagrammatic illustration of a centrifugal fan or c'ompressordischarging through a pipe leading to a reservoir, the discharge pipe being equipped with a check-valve having also an automatic reflavoring in the discharge duct, independent of any action of the check-valve.

Like parts are 'designated'by" similar letters of reference throughout the several views. 1

Referring first to Fig. 1, the centrifugal fan or compressor a driven, by the-turbine engine 6, draws air from the" atmosphere and discharges into the pipe 0 which leads lief-valve associated therewith, Fig. is a to a reservoir d. A combined check-and"- autor'natic rellef-valve is inter pused in the pipe c, "the detailed constructionthereof being clearly shown in The checkvalve e is arranged with --="a' recip'roc'ating' valve-stem 7 adapted 'to-"abut' against the valve-stem g of the re'lief-valve"hl-- A spring -h tends normally to prcs t'he} relief=valve against its seat to close the independcn't'outlet p. The check valve' is also-provided with a spring a tending topreSs-it again'St-Tits seat and thus to" close the normal dischargepas sage to the reservoir (1. The"; spring- '6 upon ing spring 7L1 upon the relief-valve,*-so"that the cl1eck-valve"in' closing will open 'the relief-valve against th-etension of said spring 71 NVhen the discharge from the compressor a' is strong enoug11.-- .co raise the check-valve from its seat-,"- the' pressure of valve may be simply "exhausted 1 =into the atmosphere, or if it is a gas a belsaved, it

maybe led back throughapipeto the -in-- take of the compressor. T he'discharge pipe for the independent outlet may? be PIOVldQd its'ste'm against the stem of-therelief' valve with a valve,.if desired, to control the flow therethrough.

It will be understood that th flow through the independent outlet- ;0. is restrioted, as by means of'the valvein the discharge pipe connected thereto, and the small size of the latter 'incompariso-n with the discharge pipe 0, to prevent an undesirable lowering of the pressure on the outlet side of the compressor when the independent outlet is open.

- through With apparatus described; the volume. at fluid taken by the alis orhi iig ap ar t s 1 of Fig. .1 plus the volume .bf

volume of flow, determined by experience or experiments, at which the blower is liable to give undesirable pulsations in flow. In the construction shown in Fig. 2, the relief-valve h is 'operated'by a check valve which is adapted to perform the usual fun0- tion of a check or non-return valve. It is apparent, however, that in so far as the present invention is concerned, the essential characteristic of -the Operating device for the relief valve hemployed in Fig. 2, isnot its capacity for directly preventingback flow' throu h the main delivery duct, but in its capacity for changing its position as the volume of flow through the main delivery duct varies, so that the relief valve h is operated in response to'variations in the volume or quantity of fluid flowing through the main.

delivery duct. F

. It is apparent, of course, that means quite difl'erentfrom that shown in Fig. 2 might be employed for operating-the relief valve in response toYvariations in the volume of flow through the main'delivery duct, an d in Fi 3 I have illustrated a construct on in whic the relief-valve instead of being operated directly by the check-valve, has its stem connected'to apiston K working in a cylinder K? in response to changes in pressurethereon.

V duct 0, conveyed-through a tube I, while the lower face of said piston-is subjected to a pressure equal to the static pressure of the fluid plus its dynamic pressure due to ve-.

locity, which combined pressure is made manifest by a Pitot tube m having its openend facing the stream oflfluid in the pipe, and communicating at its other end with the cylinder K underneath the piston. \In this.

arrangement, when the velocity of the fluid in the pipe 0 falls. below a predetermined point, a spring 0, acting downwardly on the piston K will overcome the pressure conveyed to the Pitot tube m and will forceopen the relief-valve. A subsequent increase in the velocity of the fluid will cause the pressureon the lower face of the piston to increase until the tension of'said spring 0 will overcome'and the relief-valve again closed.

In .the operation of the compressor equipped with a relief-valve such as above described, when the check-valve is'closed, or when for any reasonthe pressure conditions are such as would ordinarily give rise to surging, the opening. of the supplementary s a d pa n the relief outlet is, never-less than v r a definite minimum. whic should exceed the The upper vface of; the piston is sub-j jected to the static pressure in the discharge outlet provides for a continuous efllux of fluid sufiicient to-suppress any such tendency.

discharge, from said impeller, of a restricted relief outlet opening from said duct, a re lief valve arranged: to open and close said 1.11118 eombination'with fluid impeller 1 of, the turbine type and a duct receiving the outlet and actuating-means for said valve responsive to the volume of flow through said duct and adapted to open and close said valve as said volume decreases from and rises to a predetermined amount.

2. The combinationv with a fluid impeller of the turbine type and a-reservoir, of a pipe receiving the discharge from said compressor and leading to 'said IGSBIVOlIfSaT Id pipe having an independent outlet, a valve controlling said independent outlet, and

means acted upon positively by the static pressure ofthe discharge and the dynamic pressure thereof, arranged tooperate said valve in accordance withthe amount of fluid discharged by the compressor.

3. An automatic relief valve apparatus, comprising a pipe having a.relief opening, a valve controlling said relief opening, a chamber having amovable part, sensitive to fluid pressure, connected to' 'saidflvalve to operate the same, a tube conveyin the static pressure in the pipe to one side 0 said movable part, and'a second tube transmitting the total pressure of .the; fluid, both static and dynamic, and connected with said chamher on the opposite side of said movable Part. v I

compressor, of a pipe receiving the discharge from said compressor and leading to a reservoir, said pipe havin an independent outlet, a valve controlling said independent outlet, and means acted upon oppositely by theistatic pressure of the discharge in said pipe, connected with said chamber on the opposite side of said movable art.

In witness thereof I hereunto su scribe my name-this 5th day of August, A. D. 1908.

V AUGUSTE' CAMILLE EDMOND Ri'rEiU. V

Witnessesi HANSON G. Coxn, J oH v BAKER.

4. The combination with a centrifugal- 

